Mining soluble salt



Aug. 22, 1933. TRUMP I 1,923,896

MINING SOLUBLE SALT I I Filed Nov. 1051951 2 Sheets-Sheet 1 Inderzlor:Zdzdardik'fiump, g7 M flfibrng.

Aug. 22, 1933. TRUMP 1,923,896-

MINING SOLUBLE SALT Filed Nov. 10, 1931 2 Sheets-Sheet 2 P 1P W I WE g aI" .3 11' .4.

y j Indemnmardmflm Patented Aug. 22, 1933 IVHNING SOLUBLE SALT Edward N.Trump, Syracuse, N. 'Y.

Application November 10, 1931 Serial No. 574,149

6 Claims. (Cl. 262-3) The invention relates to improvements in' methodand means for mining soluble salts or similar materials.

The object is to provide a new and useful 5 method of operation andarrangement of well casings which will control the level of water orother liquid, while it is dissolving salts or other soluble minerals toproduce brine or other solutions.

By means of the control of level, I am enabled to dissolve out a sectionof the bottom layers of the bed of minerals such asrock salt, sulphur orpotash salts and am thus able to afterwards attack succeeding upperlayers of the salts from below.

While the following description is .given by way of example as appliedto operation upon salt beds, it will be understood that it will equallyapply to other soluble materials.

2 The method now in use for dissolving -these salts by means of wellsdrilled through the bed requires the circulation of liquid throughcasings either to the top or bottom of the bed by superior pressure. Ifthe liquid is introduced at the top of the bed it creeps out under theinsoluble roof until it comes in contact with the salt and, becomingheavy with the salt dissolved, falls and is forced back to the centercirculating tube and up to the top of the well. v

Because the fresliliquid dissolves faster than more saturated brine, theshape of the cavity becomes an inverted cone.

.As the top increases in diameter the support of the shale or rock roofis removed and caving takes place which cuts off the tubes and coversthe surface of the salt below hindering further dissolving and requiringexpensive cleaning and drilling to put back the tubing at the fulldepth.

With a very thick bed of .salt, 200 ft., it is possible to introduce theliquid at the bottom forcing it out the annular space around the centertube, making a ball shaped cavity-which will support the roof a longertime.

With a thin bed of salt the liquid rises to the top before it issaturated andthe first method must be followed. If there is considerableinsoluble material in the bed, the sides of the cone or ball are coveredand protected from the liquid and the well gradually loses capacity andis finally abandoned. I

Even if the salt is pure, the saturated brine protects the salt belowand it is dissolved Very slowly if attacked from above.

'to undercut a rock salt bed as an example in a If the salt is attackedfrom below, the saturated brine falls away and fresh liquid reaches thesalt so that solution takes place much more rapidly. The object of myinvention is to provide a method of dissolving a section of the lowerpart of the bed by attacking it radially from the well for a verylimited height.

.crease about .5 ft. per day, or in one year it will have a diameter ofnearly 360 ft. This is about the limit of rock salt roof without caving.

My invention consists of the maintenance of a layer of air, gas or otherfluid medium which will float on the liquid protecting the roof of thecavity and preventing the liquid from coming in contact with it. Thislayer is formed by introducing the medium so as to force the liquid downto the desired level and to'provide a surplus over the volume of mediumso required which will be absorbed by the liquid so that the escape ofthe surplus will automatically control the level. The level'can also becontrolled by the pressure of medium in the cavity.

Referring to the drawings, which illustrate merely by way of examplepreferred means for efiecting the invention:--

Fig. 1 .is a diagrammatic vertical section showing one form ofembodiment.

Fig. 2 is a similar view of another form.

Fig. 3 is a similar view of another form.

Fig. 4 is a similar. view of another form.

Similar numerals) refer to similar parts throughout the several views.Fig. 1. The well is cased 'with 10" tube 7 through gravel into rock. An8" casing 8 cemented into lower part of shale roof and upper part ofsalt bed. 'A 6" casing 9 to the top of the undercutand a 3' tube 10 tobottom of' the salt,

1500 ft. well with ft. of salt.

With the arrangement shown in Fig. 1, the water, at pressure of about200 pounds tothe square inch, is pumped into the 3" tube or casing 10,passing into the cavity where it circulates and dissolves salt off ofthe circumference of the cavity and flows upwards through the annularspace between the tubes 9 and 10, as partially saturated brine.

To prevent attack of thesalt above the end of the tube 9, air, of about700 pounds per square inch pressure, is pumped into the annular spacebetween tubes 8 and 9, forcing the water down until the air bubblesunder the end of tube 9. This will maintain the water level at thislevel and an air cushion will fill the space between the ripples on topof the brine as long as there is a.

surplus of air kept moving into the tube 9.

I have indicated in the drawings the colors red, blue, green and yellow,in accordance with the oflicial chart. The color red indicates air orother fluid medium for separating the solvent from the soluble; blueindicates water or other solvent; green represents sulphur water, andyellow indicates brine or solution.

In the modification shown in Fig. 2, the well is piped with a 3" tube 11to bottom of the salt and a 6" tube 12 is packed off in the 8" tube 13which is cemented in the rock. The 6" tube 12 may be stopped at the topof the salt or extended down intoit to top of the undercut. The well isoperated by forcing water down annular space between tubes 11 and 12 andbrine out of tube 11. Air is forced in with the water-and entrained inthe form of bubbles which reduce in size by ab- 1 sorption and increaseof pressure. The air is therefore compressed to the pressure of thewater at the bottom of the well and holds back the liquid to requiredlevel.

Small holes 13 in tube 11 at level of top of undercut allow surplus airto escape into the brine regulating the level of air which fills spacearound tubes to underside of packer. This arrangement reduces thepressure of air needed to the pressure of the water at top of wellinstead of the bottom as in Fig. 1.

In accordance with the modification shown in Fig. 3, the 3" tube 14,reaching to the bottom of the salt, is provided with a bell 15 which iseither part of the 6" tube 16 or will slide down through it. This bellreceives the surplus air at the level of the top of the undercut andtransfers it through small holes or passages 17 to the inside of the 3"tube 14.

The water is forced down through the annular space between the tubes 14and 16 and out through holes or space 18 above the bell 15.

Air is forced through the crown of small tube 19 into the water and iscarried down entrained as small bubbles increasing in pressure.

The amout of air absorbed increases with the depth and pressure of thewater. As the salt dissolves it drives out a portion of the air whichhas been dissolved. If a surplus of air over the amount absorbed, anyleakage and the volume required to fill the space around the tube up tothe packer is forced in, the surplus escapes under the bell and enteringthe tube 14, helps elevate the brine passing up this tube.

, In accordance with the modification shown in Fig. 4, the 8" casing 20is cemented into the rock and the top of the rock salt bed.

A 6 casing 21 is extended down nearly to the level of the undercut.

A 3" tube 22 extends to the bottom of the salt. The connections of waterand brine and air pipe are arranged so that the well can be operatedeither way, with brine or water in the 3" tube 22.

A 1" pipe 23 is suspended inside the 3" tube 22, with its bottom end atthe top of desired undercut. This 1" tube 23 may be very readily movedup or down or changed in position, to

regulate the level of the air cushion and consequently the top level ofthe solvent outside of the 3" tube 22.

If this pipe 23 is wide open, the level of thetop of the water outsidethe 3" tube 22 will be enough below the end of the 1" pipe 23 toovercome the friction of the air passing up the annular space, throughthe piping and valve and down the 1" center pipe 23.

If a reducing valve 28 shown in the air pipe is set to obstruct the air,the level of the air cushion will be lowered the amount of thedifferential pressure measured in feet of water.

With a 1500 it. well with weak brine, 18 cu. ft. of air per minute willmaintain the level with very little surplus. When the brine is saturatedonly 6 cu. ft. are required.

With this amount of air the friction in the tubing will be negligibleand the level will be very little below the end of the 1" pipe 23 whenthe reducing valve is wide open.

The above amounts are when using 20 cu. ft. of water=200 gal. per min.

In Fig. 4 are shown air gages 25 and 26, the mercury gage 27 and areducingvalve 28, the hand pump 29 and also a number of valves in theair line, the water line and the brine line, whereby the several flowsand the direction of flow may be controlled. Also the center air pipemay be arranged for change of vertical position.

By the proper manipulation of these several instrumentalities, the levelof the solvent may be regulated during the several stages as required.

This arrangement of well eliminates all packers, uses simple tubingwithout any connection between them at the bottom, and the regulation isall accomplished at the top of the well. The level can be varied atwill.

The air indicator 30, is suspended in the space betwe n pipes 20 and 21..The bottom end being below the top of the undercut. The hand air pump29 is operated to force air into the tube 30 until it bubbles under thebottom end. The difference in pressure indicated between gage 25 andgage 26, shows the distance between the water level and the bottom ofthe air indicator-pipe 30.

By soluble is meant salt or other mineral capable of being dissolved. I

By solvent is meant any fluid medium capable of dissolving the soluble.

By non-solvent is meant any fluid medium which will not dissolve thesoluble.

What I claim is:

1. In the operation of mining a soluble, wherein a solvent is introducedinto the mine, and a non-solvent is introduced into the mine to form aseparating layer between the solvent and the soluble above it, andwherein the solution is discharged from the mine, the method whichconsists in introducingthe solvent admixed with the non-solvent andutilizing the said separating layer of non-solvent for controlling thelevel of the solvent in the mine cavity.

2. In the operation of mining a soluble, wherein a solvent is introducedinto the mine, and a non-solvent is introduced into the mine to form aseparating layerbetwcen the solvent and the soluble above it, andwherein the solution is discharged from the mine, the method whichconsists in introducing the solvent and non-solvent continuously and inutilizing the said separating layer of non-solvent for controlling andchanging as required the level of the solvent in the mine cavity.

3. In the operation of mining a soluble, wherein a continuous supply ofa solvent is introduced into the mine and also a continuous supply ofnon-solvent which will form a protecting layer between the-solvent andthe soluble above it, and which will also provide a continuouslydischarging surplus, and wherein the solution isdischarged from themine, the method which consists in utilizing the discharging surplus ofnonsolvent to cooperate in the discharge of solution, whereby therequired pressures of the introto lighten the ascending column ofsolution, so that the energy derived from the upward movement of saidascending column may be utilized in connection with the introduction ofthe solvent.

5. In the operation of mining a'soluble, wherein an admixture of asolvent and a non-solvent is introduced into the mine, the non-solventseparating from the solvent to form a protecting layer between thesoluble and the solvent, the method which consists in controlling thelevel of the solvent by the difierence in pressure of the non-solvent ata point approximate the level of the solvent and at the point ofdischarge of a surplus of the non-solvent which escapes into thedischarging solution.

6. The method of mining a soluble, which consists in introducing intothe mine cavity a supply of, solvent, and a supply of gaseous medium inexcess'of the amount that wouldbe taken up by the solvent so that thesurplus gaseous medium will be discharged from the cavity, dischargingthe solution from the cavity together with the surplus gaseous medium,and controlling as required the level of the solvent in the cavity bycontrolling the point of discharge of the surplus gaseous medium.

EDWARD N. TRUMP

